Automatic firearm breech bolt lock



H. LIPPERT ETAL AUTOMATIC FIREARM BREECH BOLT-LOCK June 20, 1950 v.2 sheets-sheet 2 Filed June 27, 1945 f vIrQIVEnWORs Hanns laffe rtm1 E aM/,1am

'ATTom/sss Patented June 20, 1950 UmransrAr es rarest. ortica y v 2,512,027l Aurrom'rIormEAnM BREEonlBoLTS-Look Hanns Lippert and Ernst Mhlemann, Zurich,

Switzerland, assignors to VerWaltun-gsgesellschaftrder Werkzeugmaschinenfabrik Oerlikon, .Zurich- Oerlikon, Switzerland Application June 2.7, 1945,:seria1iNo. 26013773 YInSwitzerland July '8, 1944 lfclaim. -1

This invention vrelates to automatic firearms. The invention refers more particularly to gasoperated 4guns ofthe type displosed, for example, IltUgiS. Patent No. 784,966.

.Agrigidly locked weapon is known, in which the breech .block is locked .by a swivelling bolt, theswivelling movement being caused by at least one crank web tted to .the `locking bolt; the Acranlcpinoi the `crank web acts at the same time as algui-dingpivot and -slidesin a corresponding guiding .groove -of .the'casing :In this constructionithe .locking bolt slidesxby means of one-sided tonguesin a guiding grooveof the breech casing. This .guiding groove vends in a round hole in which the.locking 'boltcan swivel in the manner described, coming into .contact with the Abreech casing and thus eiiecting the locking process.

Weaponsare alsoknown, in which the breech blockconsists of two :parts and the locking and release of a locking organ are controlled by the movements of the two breech parts towards, or awayirom, keach other- Such weapons `aredescribed, for example, in British Patent No. 575,515.

An object of the present invention is to provFig 8 shows 1the ymechanism forstarting the unlocking process, i-n its position 'inthe recoil stroke.

LF-ig.\'9 is a lperspective view `of the locking bolt in locked-position.

EFig.-110isa-perspective-view of the lockingbolt in -unlocked position. i

The barrel l-l is-rigidlytted in known manner in -the-breech-casing 2. The ybreech block 3 and the vlock-actuator l slide-inthe breech casing; a spring '5 is supported i-n the rear part of the breech casing 2. The breech casing v2 further includes thetrigger actuated in known manner. The `breech Icasing 2 is mounted by means of shoulders 1, 1'8in a vcradled, in ywhich it is able l to recoil 'again-st' the lspring lll. 'The cylindrical vide anautomatic lire-arm combining the above mentioned characteristics of known weapons. since it has been found that through a suitable combination of .these two known `characteristics aparticularly simple and lightbreech block could be evolved. v

Theautomatic iire-armzaccording to the present invention includes a split block body permit ting the displacement of` the various parts in relation 4to each other: the front part includes a rotatably -mounted locking -bolt sliding through its milled ends in a guiding groove of the breech casing terminating in a round hole, and carrying gear teeth in engagement with a gear rack rigidly connected with the lock actuator carrying the hammer, the control taking place through the movements of the block and lock actuator in relation to each other.

The enclosed drawing shows constructional example of the subject of the invention.

Fig. 1 is a schematic section through a weapon with locked breech block.

Fig. 2 shows the weapon according to Fig. l with unlocked ybreech block, in the recoil stroke.

Fig. 3 is a section through the breech block in locked position.

Fig. 4 is a section along line 4--4 in Fig. 3.

Fig. 5 shows the unlocking mechanism.

Fig. 6 is a section through the breech block in unlocked position.

Fig. '7 is a section along line 'l--1 in Fig. 6.

`locking lbolt H Ais seated yin a hole yin the front breech block 3. The locking bolt Il is provided with a recess -I`-2 into which engages an inserted piece -|31-which thus prevents l'the bolt `from moving transversely and from falling vout;

The fbreech block 3 projects into the lock actuator-llby means of 4av-projectionlll. The pro- 'ection i4 carries shoulders l5 sliding -in a hole Nfof the lloc-k actuator -llfand staggered in -relation to the shoulders l1, so Ithat'the breech block and-the lock actuator can be inserted into each other 4in the Tmanner of Va bayonet joint.

-As can be seen from Fig. 3, the movement of the breech vv`block'and 'the-lock actuator is limited bylthe shoulders I5 on the breech block 3, and by the vshoulders vlil on the lock actuator 4. A gear -rack v|28 is rigidly connected with the lock actuator; yit'carries at lits `-frontend the ring pin 19 'sea-ted iin va 4corresponding hole of the breech block 3. The gear rack I8 engages gear teeth 20 of the bolt Il. The extractor 2l is rotatably mounted in the breech block 3 by means of a pin 22., The extractor 2| stands under the action of a spring 23 inserted in a hole in the breech block 3. That part of the lock actuator 4 which engages below the breech block 3 has a hollow space 24 in which is tted a T-piece 25 standing under the action of the two springs 26 supported on a front wall of the lock actuator. To the T-piece 25 is iitted a pin 21 projecting through a slot 28 into a hole 29 of the breech block 3 and engaged by a spring 30 fitted in this hole 29. The bolt Il is provided with two milled ends 3|, 32, through which it slides in grooves 33 of the breech casing, ending in a hole 34. The breech block 3 is furthermore provided on its upper face with a stripper 36 rotatably mounted upon a pin 35 and permanently pressed upwards under the action of a spring 31; this 40 with its rod 4I pivoted to a toggle lever 42 by a pin 43. In the hollow cylinder is arranged a spring 44 projecting into a hole of the piston 40, and tending to force the latter outwards. The toggle lever 42 is swingably mounted on'the breech casing by means vof the pin 45. The lever 42, through the cam 46, comes into contact with a part 41 rigidly connected with the mounting during the rearward movement of thel barrel.

The working of the breech block is briefly as follows: y

-In the locked position, as shown in Fig. 3, the bolt II occupies the position represented in perspective in Fig. 9 and, through its shoulders 3|, 32 is in close contact with the vbreech casing. After the firing the barrel slides rearward. As a result the cam 46 comes into contact with the part 41 rigidly connected with the cradle and revolves round the axis of rotation 45, and therefore under the actionof the lever 42, the lock actuator4 with which it is in contact, is moved rearwards at a speed exceeding by a gradually increasing extent the speed with which the breech block Sis traveling backwards together with the barrel. As soon as there is relative movement between the breech block 3 and the lock actuator 4, the bolt I I begins to rotate under the action of the gear rack I8. The bolt I I with its shoulders 3I` and 32 is moved into the position shown in Fig. l and is consequently enabled to slide rear- 4 nition has also taken place, since the gear rack I8 carries the striker as well.

The pin 21 lodged in the breech block 3, in conjunction with the T-piece 25 which, under the actionof the springs 2B, is in vcontactawith the lock actuator 4,"insures that .the breech block 3 will always stand under strain in relation to the I lock actuator 4, since under the action of the springs 26 the breech block and the lock actuator lare permanently drawn toward each other.

As can be seen from the description, the breech block accordingl to the present invention is of n extremely simple' design; it includes only a few wards in the guiding grooves 33. The unlocking is thus effected. 1

In its rearmost position the breech is again impelled forward by the spring 5. In travelling forward the breech block 3 strikes the cartridge chamber and breech casing and again a relativev movement takes place between the breech block 3 and lockl actuator 4, since the lock actuator 4 now'moves forward in relation to the stationary breech block 3 until the shoulders I5 come into contact with the shoulders I1. Now through the block actuator 4 moving toward the breech block 3, the bolt II is caused to revolve under the action of the gear rack I8, and the shoulders 3l, 32, come again into contact with the breech casing as shown in Fig. 9, thus effecting the locking. Simultaneously with the forward travel igparts and can therefore be made of light weight.

Obviously there would not be the slightest dif- `iiculty in using, in lieu of the mechanism shown in Figs. 5 and 8, other driving means or one of the known gas unlocking mechanisms; in other words, the breech block as described can also easily be used in a gas-operated gun.

We claim: Y

- In anautomatic nre-arm, locking means comprising in combination a breech block, a locking bolt rotatably mounted in Said breech block and having milled ends and gear teeth; a breech casing having guiding grooves formed therein and receiving said milledends, said breech casing further havingY a round. hole formed therein and in communication with said 'guiding grooves, a lock actuator movable in relation to said breech block, a gear rack rigidly connected with said lock actuator and meshing with said gear teeth, and a lir-A ing pin carried by said gear rack, said milled ends being rotated in said round hole by the gear rack to effect the'locking and the release oi the locking means. Y

yI-IANNS LIFPERT.

ERNST MUHLEMANN.

REFERENCES CTED The following references are [of record in the iile of this patent:

UNITED STATES PATENTS 

